1. Field
The present disclosure is directed to a method and apparatus for alert message reception. More particularly, the present disclosure is directed to receiving cellular public warning system messages or other messages at user equipment.
2. Introduction
User equipment, cell phones, smart phones, tablet computers, personal digital assistants, personal computers, and other user equipment, can operate on cellular networks, Wireless Local Area Networks (WLAN) such as those based on the IEEE 802.11 standard, and other networks. When operating on a cellular network, Commercial Mobile Alerting System (CMAS)-capable user equipment can receive CMAS messages. CMAS is an opt-out system that sends CMAS alerts, such as Presidential, Extreme, Severe, and Amber alerts, to user equipment. By default, CMAS-capable user equipment can receive all types of CMAS alerts, but the user can opt out, via a menu, of the Extreme, Severe, and Amber alerts; receive capability for the Presidential alert is mandatory. CMAS alerts are geo-targeted by the carriers of cellular networks, with cell-level granularity, based on coverage area indicators sent by a government entity originating the alert. Such government entities can include the National Oceanic and Atmospheric Administration (NOAA), the Federal Emergency Management Agency (FEMA), the Department of Defense (DOD), the President of the United States, the National Weather Service (NWS), and other government entities. The CMAS alerts provide timely and accurate alerts, warnings, and critical information regarding disasters and other emergencies.
User equipment can only receive CMAS alerts over a cellular network. This means that user equipment that connects to a WLAN and disconnects from a cellular network cannot receive the alerts. Furthermore, user equipment that operates only on WLANs cannot receive the CMAS alerts. This also holds true for user equipment that are cellular network-capable, but do not have cellular network coverage. For example, a cellular network-capable user equipment may power up in a location where a WLAN is available and the user equipment may connect to the WLAN without connecting to a cellular network. Alternately, the user equipment may be configured to prefer a WLAN connection even when cellular network coverage is available. The user equipment may still make calls using Voice over Internet Protocol (VoIP) over the WLAN, but if it does not connect to the cellular network, the user equipment will not receive CMAS alerts.
Other regions of the world have, or will have, similar systems to CMAS, such as the Earthquake/Tsunami Warning System (ETWS) in Japan, the European Union EU-Alert system in Europe, and the Korean Public Alert System (KPAS) in Korea. In 3rd Generation Partnership Project (3GPP) standards, common requirements for these systems are covered by Public Warning System (PWS) specifications. These systems also cannot send warning messages over a WLAN.
To elaborate on one example, when user equipment has a WLAN-only mode, cellular network carriers can require or encourage the user equipment to switch to a WLAN-only mode to reduce data traffic over the cellular network. These carriers have, or are planning to deploy, trusted WLAN networks in malls, enterprises, airports, and other locations as the carriers strive to offload data to WLAN. User equipment voice services are then conducted over WLAN using, by example, an Internet Protocol (IP) Multimedia Subsystem (IMS) client on the user equipment by re-registering with an IMS network after reselection to WLAN occurs. Alternately, the user may prefer a non-IMS VoIP client such as Skype, which can operate on any wireless or wired data network. The UE can then de-attach from the cellular network while in WLAN mode to improve battery life and data throughput. Unfortunately, this leaves the user exposed to the inability to receive CMAS alerts while in WLAN mode. In order to avoid this incapability, the user equipment may, while using WLAN for data and VoIP, leave the cellular modem registered to the cellular network solely for the purpose of receiving CMAS alerts. This arrangement wastes power, and also may create RF interference scenarios on the user equipment when both the cellular and WLAN transceivers are simultaneously active.
Thus, there is a need for an improved method and apparatus for alert message reception.